Pistons

Pistons were aluminum alloy; they were a closed slipper-type, steel strut, ellipitcally-turned, and tin-plated.

Model

170 (6-cyl)

225 (6-cyl)

273 (V-8)

318 (V-8)

Weight (piston only ) oz.

16.4

16.4

19.3

20.9

Clearance (limits) Top land

.024 min.

.024 min.

.017 min.

.018 min.

Clearance (limits) Skirt Top

.0005 - .0015

.0005 - .0015

.0005 - .0015

.0005 - .0015

Clearance (limits) Skirt Bottom

-.0005 - +.0005

-.0005 - +.0005

-.0005 - +.0005

-.0005 - +.0005

Ring groove depth No. 1 and No. 2 ring

.179

.179

.191

.205

Ring groove depth No. 3 ring

.181

.181

.182

.193

Rings

From top to bottom, ring #1 and #2 were for compression, #3 was for oil. Compression rings were cast iron, lubrite-coated; all #2 rings had reverse twist and taper. Compression width was 0.078 and gap was 0.010 - 0.020. Oil ring width was 0.188.

Engine lubrication

Piston pins and cylinder walls were given a metered jet spray; pressure lubrication was used on main bearings, connecting rods, cam bearings, and, on V8s only, tappets (slant sixes had splash lubrication for tappets). Normal oil pressure was 45-65 psi at 2,000 rpm. The oil pressure sending unit was electrical; the oil intake was stationery, and the fuel filter was full-flow.

1968 Valiant Exhaust specifications

Model

Slant Six

273 and 318 V8

Type (single, single w/cross-over, dual, other)

Single

Single w/cross-over

Muffler

One, reverse flow

One, reverse flow

Exhaust pipe dia. – O.D., wall thick. (Branch)

-

1.75 x .075

Exhaust pipe dia. – O.D., wall thick. (Main)

1.88 x .075

2.00 x .075

Tail pipe dia. (O.D. & wall thickness)

1.75 x .043

1.88 x .043

Crankcase ventilation systems

All engines used induction-stype crankcase ventilation, with a cylinder-head cover outlet, controlled by a variable orifice; it took air in from the air cleaner (via a tube going to the oil filler cap) and discharged at the intake manifold, at or below the carburetor base. A check valve acted as a flame arrestor.

Every 6 months, owners were to inspect the crankcase ventilator valve, oil filler pipe cap, and associated hoses, clean the oil filler cap, and test the ventilator valve for proper operation; the crankcase ventilator valve was to be replaced every year.

Fuel systems and carburetors

All models used an 18 gallon (US) tank, with a filler outside the left rear fender; the fuel pump was mechanical, with pressure of 3.5 to 5 psi for slant six, and 5 to 7 psi for V8s. Both a fuel tank and fuel supply filters were used. Carburetors had separate automatic chokes, with heat control from the exhaust.

170

225

273

318

Idle speed – Manual*

750

650

700

650

Idle speed– Automatic*

750

650

650

600

Idle air-fuel mixture*

14.0 – 14.4

14.0 – 14.4

14.0 – 14.4

14.0 – 14.4

Transmission

Manual, Automatic

Manual, Automatic

Manual, Automatic

Manual, Automatic

Carburetors (Make)

Ball and Ball**

Holley

Ball and Ball**

Ball and Ball**

Carburetors (Model)

BBS-4414 S (Manual), BBS-4415 S (Automatic)

R-3919 A (Manual), R-3920 A (Automatic)

BBD-4416 S (Manual), BBD-4417 S (Automatic)

BBD-4420 S (Manual), BBD-4421 S (Automatic)

No. used and type

1, 1-bbl

1, 1-bbl

1, 2-bbl

1, 2-bbl

Barrel Size

1.56 (Manual), 1.69 (Automatic)

1.69

1.44

1.44

* Air conditioner off, transmission in neutral.

** Ball and Ball, a supplier to Chrysler from antiquity, was acquired by Carter, which renamed its carburetors “BBD.”

Timing

170 Manual

170 Auto.

225 Manual

225 Auto.

273 Manual

273 Auto.

318 Manual

318 Auto.

Timing (Degrees)

5 ATC

2.5 ATC

TDC

TDC

5 ATC

2.5 ATC

5 ATC

2.5 ATC

Timing (@RPM)

700

700

650

650

700

650

650

600

Distributor

2875199

2875202

2875364

2875366

2875334

2875334

2875342

2875342

Spark advance

Distributor Part No.

Centrifugal Advance (Crank ° @ RPM)

Vacuum Advance (Crank ° @ Inches of Mercury)

Start

Intermediate

Maximum

Start

Intermediate

Maximum

2875199

0 @ 700-1000

0-7.4 @ 1000, 24.4-28 @ 1980

34-38 @ 4400

0 @ 5-7.1

6-12 @ 8.5

12-17 @ 10

2875202

0 @ 700-1000

0-13.4 @ 1000, 18.4-22.4@1420

28-32 @ 4400

0 @ 5-7.1

6-12 @ 8.5

12-17 @ 10

2875334

0 @ 700-1000

0-14 @ 1000, 22.5-26.5@1470

31-35 @ 3800

0 @ 5-8

10-16 @ 10

21-27 @ 13.5

2875342

0 @ 650-950

0-10 @ 950, 15.5-19.5@1400

36-40 @ 4700

0 @ 8.1-9.8

8-14 @ 12.2

16.5-21.5 @ 15

2875364

0 @ 700-1000

0-7.4 @ 1000, 18.4-22.4@1740

25-29 @ 4000

0 @ 6.2-9.7

4-10 @ 11.9

7.4-12.4 @ 13.8

2875366

0 @ 700-1000

0-7.4 @ 1000, 18.4-22.4@1740

25-29 @ 4000

0 @ 5-7

5-11 @ 8

7.4-12.5 @ 8.7

Manual transmission

All clutches were dry-plate, with oil pressure plate springs, and a facing of woven asbestos. Release bearings were permanently lubricated ball bearings. Torsion damping was done by coil springs with friction washers.

Clutch

Slant Six

273 and slant six optional

318 3-speed

318 4-speed

Make & Type

Auburn

Auburn

Borg & Beck

Borg & Beck

Type Pressure plate springs

Coil

Coil

Coil

Coil

Total spring load (lb.) min.

1330

1600

1992

2345

Clutch Facing and Area

9.25 x 6.0 / 77.8

9.5 x 6.5 / 75.4

10.0 x 6.0 / 100.5

10.5 x 6.5 / 106.8

Clutch Facing Thickness

.114

.114

.130

.125

Engagement cushioning method

Two-piece cushion

Two-piece cushion

Flat wave springs

Flat wave springs

Suspension

All models used torsion-bar suspension, adjustable via anchor bolt; brake dip and acceleration squat was controlled by inclined upper control arms and asymmetrical rear springs. Shock absorbers were direct-acting and made by Chrysler, with a 1-inch piston diameter. The front suspension was independent, with non-parallel control arms. Torsion bars were made of chromium alloy steel. A 0.88-inch diameter link-type front stabilizer was optional.

Front ball joints were to be lubricated every three years or 36,000 miles and inspected twice a year. Lubricant was P/N 2525035.

The rear suspension used parallel, longitudinal leaf springs, of a semi-elliptical, asymmetrical design, made of chromium alloy steel. They were 55 inches long and 2.5 inches wide in each case. The spring rate was 85 lb/square inch (105 at the wheel) on all but the 318, which used a 110 lb/square inch rate (132 at the wheel). Rubber mountings were used; Chrysler warned not to lubricate the rear springs, spring eye or shackle bushings, or shock absorber bushings.